3. Bowman's Capsule: where ultra-filtration begins.
a) Blood arrives in the kidney in the Afferent arteriole - at high pressure - (with a wide blood vessel).
b) Blood passes through the Glomerulus and pases out the Efferent arteriole - (with a narrow blood vessel.)
c) Blood pressure increases in the Glomerulus.
d) High pressure forces the plasma (liquid in blood - water, salts, amino acids, glucose and urea) out of the blood vessel into the inside of the Bowman's Capsule - This is called "Glomerula Filtrate."